Machine for making metal tubes
Abstract
Abstract A SERIES OF DRIVE ROLLERS ARE PROVIDED TO FEED A METAL STRIP ALONG A HELICAL PATH AROUND A ROTATING MANDREL. THE STRIP HAS AN UPSTANDING LONGITUDINAL FLANGE ALONG ONE EDGE THEREOF AND A U-SHAPED LONGITUDINAL FLANGE ALONG THE OTHER EDGE, ADAPTED TO INTERLOCK WITH THE UPSTANDING FLANGE. THE STRIP IS ALSO FORMED WITH AN INTERMEDIATE LONGITUDINAL CONVOLUTION SO THAT THE TUBE WILL BE FLEXIBLE. THE DRIVE ROLLERS ARE DRIVEN AT A SURFACE SPEED GREATER THAN THAT OF THE MANDREL AND ARE ANGLED IN ACCORDANCE WITH THE HELICAL PITCH ANGLE OF THE STRIP. A STATIONARY MEMBER WITH A HELICAL SURFACE IS DISPOSED AROUND THE MANDREL TO GUIDE THE EDGE OF THE STRIP. THE FLANGES ARE INTERLOCKED AND THEN BENT INWARDLY AT AN ANGLE BETWEEN A THIN CONICAL ROLLER AND ONE OF THE DRIVE ROLLERS WHICH HAS A FRUSTO-CONICAL SURFACE. THE BENT FLANGES ARE FLATTENED BY A ROLLER WHICH IS ANGLED MORE SHARPLY THAN THE DRIVE ROLLERS.
Inventors
- 👤 Domenico Parma
Bibliographic Details
Claims Analysis
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-09-20 | 1975-03-22 | 1975-09-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-09-20 | 1979-03-22 | 1979-09-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-09-20 | 1983-03-22 | 1983-09-21 | $7700.00 | Window Closed / Lapsed |